BW MCXL-XWHM-Y-NA GasAlertMicroClip XL 4-Gas Personal Gas Detector, %LEL, O2, H2S, CO Model: MCXL-XWHM-Y-NA This personal gas detector alerts users of dangerous levels of Hydrogen Sulfide, Carbon Monoxide, Oxygen, and Combustible Gasses in their work area. The simple one button operation minimizes the need for training and gets workers on the job faster. Extended 18 hour battery run time keeps workers safe for longer. Beeping alone while working in a loud environment might not always be enough but with the visible flashing green IntelliFlash™ workers are notified of the dangers.